How to duplicates in database using SQL Server

I have a database where I have data and I would like to get all those duplicate values (I meant which appears twice).

This is my code

DbCommand cmd = db.GetSqlStringCommand("SELECT * FROM RewriteTable where OriginalUrl like '%@rowValue%'");
db.AddInParameter(cmd, "original", DbType.String, rowValue);
DataSet ds = db.ExecuteDataSet(cmd);
return ds;

But it's not showing any duplicates even if not present